3 files changed, 55 insertions, 0 deletions
diff --git a/classes/IsisConnector.php b/classes/IsisConnector.php
index cc4bf62..c731d9a 100644
--- a/classes/IsisConnector.php
+++ b/classes/IsisConnector.php
@@ -543,4 +543,43 @@ class IsisConnector {
 
     return false;
   }
+
+  /**
+   * Deal with special subfields.
+   *
+   * @param $field
+   *   Field data from ISIS database schema.
+   *
+   * @param $subfield
+   *   Subfield name.
+   *
+   * @param $return
+   *   Specify return type.
+   *
+   * @return
+   *   True if special subfield, false otherwise of special return type
+   */
+  public function specialSubfield($field, $subfield, $return = 'boolean') {
+    if (isset($field['special'])) {
+      $field_key    = $this->getFieldKey($field);
+      $subfield_key = $this->getSubfieldKey($field, $subfield);
+      $name         = $field['name'] .':'. $subfield;
+      $code         = $field_key .':'. $subfield_key;
+
+      if (array_search($subfield_key, $field['special'])) {
+        $this->log("Found special subfield $name", 'debug');
+
+        if ($return == 'boolean') {
+          return true;
+        }
+        elseif ($return == 'code') {
+          return $code;
+        }
+
+        return $name;
+      }
+    }
+
+    return false;
+  }
 }
diff --git a/classes/IsisNormalSubfieldFilterIterator.php b/classes/IsisNormalSubfieldFilterIterator.php
new file mode 100644
index 0000000..98494a6
--- /dev/null
+++ b/classes/IsisNormalSubfieldFilterIterator.php
@@ -0,0 +1,14 @@
+<?php
+
+/**
+ * Isis normal subfield iterator. Filter out special subfields.
+ */
+class IsisNormalSubfieldFilterIterator extends FilterIterator {
+  public function accept()
+  {
+    $field    = $this->getInnerIterator()->field;
+    $class    = $this->getInnerIterator()->class;
+    $subfield = $this->getInnerIterator()->current();
+    return !$class->specialSubfield($field, $subfield);
+  }
+}
diff --git a/classes/IsisSubfieldIterator.php b/classes/IsisSubfieldIterator.php
index 8a35399..36d3d06 100644
--- a/classes/IsisSubfieldIterator.php
+++ b/classes/IsisSubfieldIterator.php
@@ -23,6 +23,8 @@ class IsisSubfieldIterator implements Iterator
    *   Field to iterate over.
    */ 
   public function __construct($class, $field) {
+    $this->class     = $class;
+    $this->field     = $field;
     $this->rows      = $class->getRows($field);
     $this->fieldset  = $class->getSubfieldList($field);
     $this->keys      = array_keys($this->fieldset);